Method for identifying markers

ABSTRACT

The invention relates to a method and to a device for identifying markers in data blocks. The method is characterized in that a number of data blocks ( 201   a    201   n ) are received by a receiver ( 202 ) and one specific data block from the number of data blocks ( 201   a    201   n ) is analyzed in order to determine whether the specific data block contains a marker ( 203 ) or not. Once a data block that contains a marker ( 203 ) is identified, a full-rate signaling block ( 206 ) that is transmitted at full rate and a half-rate signaling block ( 207 ) that is transmitted at half rate are searched for markers. A predetermined reference pattern is provided for correlation that is subsequently divided into sub-ranges that in turn are correlated with a predetermined reference pattern to identify a signaling frame in the full-rate signaling blocks ( 206 ) and/or the half-rate signaling blocks ( 207 ).

[0001] The present invention relates to a method for recognition ofidentification patterns, and in particular to a method which recognizesall the important identification patterns in one or more signalingframes.

[0002] The signaling is provided in signaling frames which are in turntransmitted in a data band instead of speech frames.

[0003] A data receiver—referred to for short in the following text as a“receiver”—must be able to distinguish between the signaling framesmentioned above and speech frames.

[0004] In the method according to the prior art, this distinction ismade with the aid of specific identification patterns (also referred toas “markers”). A protocol for signaling is specified in conventionaldata transmission channels. The signaling is used, for example, for:

[0005] a) fixing different data rates;

[0006] b) switching between different data rates; and

[0007] c) DTX (discrete transmission) handling.

[0008] In general, with mixed digital transmission of speech data andother data, received data blocks must be analyzed in an appropriatereceiver. In order to save computation time and in order to ensure ahigh transmission rate, this analysis must be carried out as efficientlyand quickly as possible at the receiver end.

[0009] In order to distinguish between data blocks which transmit onlyspeech information and are therefore referred to in the following textas speech blocks, and data blocks which transmit other data orreceiver-specific information, for example the switching betweendifferent speech codes, and are thus referred to in the following textas signaling blocks, conventional receiver-end analysis systems usespecific identification patterns or “markers” in order to identifysignaling frames which are contained in the signaling blocks.

[0010]FIG. 4 shows a schematic flowchart of a method for recognition ofidentification patterns according to the prior art, in which receiveddata blocks 201 are searched sequentially in full rate signaling blocks206, with full rate signaling frames 208 a-d being set successively foridentification patterns. 401 in this case denotes a decision device forjumping back to the next full rate signaling block 206, and 103 denotesa result output step.

[0011] This method has the major disadvantage that a separate searchmust be carried out after each signaling frame, and this results in alarge amount of time being lost as a result of the long computationtime.

[0012] A further disadvantage of conventional methods is the necessityto carry out deinterleaving and recognition of identification patternsmore than once.

[0013] Yet another disadvantage of conventional methods is that all thesignaling frames must be searched for separately.

[0014] The method on which the invention is based and according to claim1 has the major advantage that identification patterns in signalingframes are recognized by means of a single correlation so that there isno need to search each signaling frame or to carry out a deinterleavingprocess and recognition of identification patterns more than once, thusmaking it possible to save a considerable amount of computation time.

[0015] The essence of the invention is a method for recognition ofidentification patterns in data blocks which have been received by meansof receivers, in order to distinguish between speech frames andsignaling frames, with correlation being subdivided using predeterminedreference patterns, and symmetries in the reference patterns to beanalyzed being used for recognition.

[0016] Advantageous developments and improvements of the respectivesubject matter of the invention are contained in the dependent claims.

[0017] According to one preferred development of the method according tothe invention, mutually inverted identification patterns need beevaluated only once, in order to save computation time.

[0018] According to a further preferred development of the methodaccording to the invention, one or more of the transmitted data blocksis a speech block or are speech blocks which contain a speech frame orspeech frames.

[0019] According to yet another preferred development of the methodaccording to the invention, one or more of the data blocks is asignaling block or are signaling blocks which contains or contain asignaling frame or signaling frames.

[0020] According to yet another preferred development of the methodaccording to the invention, deinterleaving is carried out only once.

[0021] According to yet another further preferred development of themethod according to the invention, a full rate signaling block containsone or more types of full rate signaling frames.

[0022] According to yet another preferred development of the methodaccording to the invention, a half rate signaling block contains one ormore types of half rate signaling frames.

[0023] According to yet another preferred development of the methodaccording to the invention, a sequence controller decides whether to usea calculated correlation value.

[0024] According to yet another preferred development of the methodaccording to the invention, a speech block is transmitted by means of afull rate speech block.

[0025] According to yet another preferred development of the methodaccording to the invention, a speech block is transmitted by means of ahalf rate speech block.

[0026] Exemplary embodiments of the invention will be explained in moredetail in the following description and are illustrated in the drawings,in which:

[0027]FIG. 1 shows a flowchart of the method for recognition ofidentification patterns according to the present invention;

[0028]FIG. 2 shows a block diagram illustrating the transmission of datablocks to a receiver, and providing a summary of the contents of datablocks;

[0029]FIG. 3 shows a block diagram illustrating an apparatus forrecognition of identification patterns according to the presentinvention; and

[0030]FIG. 4 shows a flowchart of a method for recognition ofidentification patterns according to the prior art.

[0031] Identical reference symbols in the figures denote identical orfunctionally identical components and sequence blocks of the methodaccording to the invention.

[0032]FIG. 1 shows a flowchart of the method for adaptive recognition ofidentification patterns in data blocks, in order to determine signalingframes, according to the present invention, in which the illustratedsequence shows, by way of example, the investigation of a data block, inthis case the data block 201 b.

[0033] A series of data blocks 201 a-201 n (FIG. 2), where the index nindicates the maximum number of data blocks under consideration, istransmitted from a transmitter (not shown) to a receiver 202 (FIG. 2).The data blocks may contain either speech information or signalinginformation. Owing to the different requirements for further processingof the data depending on whether the data is speech information orsignaling information, it is necessary to reliably distinguish betweendata blocks which contain speech information and data blocks whichcontain signaling information.

[0034] In this context, reference is also made to FIG. 2, which shows ablock diagram illustrating the transmission of data blocks to areceiver, and provides a summary of the contents of data blocks. Once aspecific data block from a series of data blocks 201 a to 201 n has beenreceived, this specific data block is analyzed in order to determinewhether this specific data block, which is illustrated as a data block201 b in FIG. 2, does or does not contain an identification pattern 203.

[0035] A data block which does not contain an identification pattern 203is then identified as a speech block 204 and is processed further inaccordance with the requirements for speech information processing. Incontrast to this, a data block which does contain an identificationpattern 203 is identified as a signaling block 205. Furthermore, asearch is carried out for identification patterns in a full ratesignaling block 206 which is transmitted at a full rate, and a search iscarried out for identification patterns in a half rate signaling block207, which is transmitted at a half rate.

[0036] According to this embodiment of the method, the search for therespective identification patterns is carried out by means of acorrelation method, with the correlation process being subdivided intoindividual correlation steps 101 a to 101 n using a correlationsubdivision device 304 (FIG. 3). In this case, a predetermined referencepattern 104 is provided for the individual correlation steps 101 a to101 n, and is processed at the same time in the individual correlationsteps 101 a to 101 n. This procedure considerably speeds up arecognition process for identification patterns in comparison to methodsaccording to the prior art, in which complete correlations need to becarried out successively, as explained above with reference to FIG. 4.Once the correlation process has been subdivided into subareas which areeach correlated with the predetermined reference pattern 104—at the sametime—individual full rate signaling frames 208 a to 208 n are found inthe full rate signaling blocks 206, and/or half rate signaling frames209 a to 209 n are found in the half rate signaling blocks 207,following which correlation values 307 (FIG. 3) are output in order toindicate signaling frames which have been found.

[0037] A sequence controller 306, which is illustrated in FIG. 3,decides which correlation value will be used.

[0038]FIG. 3 shows a block diagram illustrating an apparatus foradaptive recognition of identification patterns in data blocks in orderto determine signaling frames. A data block 201 to be analyzed is outputto an analysis device 301 once it has been received by the receiver 202,with the assumption being made in this exemplary embodiment that any ofthe data blocks 201 a to 201 n can be analyzed. The analysis device 301analyzes a specific data block from the series of data blocks 201 a-201n in order to determine whether the specific data block does or does notcontain an identification pattern 203. The specific data block is thensupplied to an identification device 302, in order to identify a datablock which does not contain an identification pattern 203 as a speechblock 204, and in order to identify a data block which does contain anidentification pattern 203 as a signaling block 205.

[0039] The output signal from the identification device 302 is thensupplied to a correlation device 303 in order to search foridentification patterns in a full rate signaling block 206, which istransmitted at a full rate, and to search for identification patterns ina half rate signaling block 207, which is transmitted at a half rate,which are contained in the full rate signaling block 206 and/or in thehalf rate signaling block 207, by means of correlation with referencepatterns 104. A correlation subdivision device 304 then subdivides thecorrelation process into subareas which in turn are correlated with apredetermined reference pattern in order to find signaling frames in thefull rate signaling blocks 206 and/or in the half rate signaling blocks207.

[0040] An output device 305 is used for outputting correlation values inorder to indicate the signaling frames which have been found. A sequencecontroller 306 controls an operating sequence and, as already mentioned,decides which correlation values 307 will be output in a current state.

[0041] Although the present invention has been described above on thebasis of preferred exemplary embodiments, it is not restricted to thembut can be modified in many ways.

[0042] List of Reference Symbols

[0043] Identical reference symbols denote identical or functionallyidentical components in the figures. 101a, . . ., 101n Individualcorrelation steps 102 Evaluation step 103 Result output step 104Reference pattern 201, 201a, . . ., 201n Data blocks 202 Receiver 203Identification pattern 204 Speech block 206 Full rate signaling block207 Fullhalf rate signaling block 208a, . . ., 208n Full rate signalingframes 209a, . . ., 209n Half rate signaling frames 210 Full rate speechblock 211 Half rate speech block 301 Analysis device 302 Identificationdevice 303 Correlation device 304 Correlation subdivision device 305Output device 306 Sequence controller 307 Correlation values 401Decision device

1. Method for recognition of identification patterns in data blocks inorder to determine signaling frames, comprising the following steps: a)Reception of a series of data blocks (201 a-201 n) in a receiver (202);b) Analysis of a specific data block from the series of data blocks (201a-201 n) in order to determine whether the specific data block containsan identification pattern (203); c) Identification of a data block whichdoes not contain an identification pattern (203) as a speech block(204); d) Identification of a data block which does contain anidentification pattern (203) as a signaling block (205); e) Search foridentification patterns in a full rate signaling block (206) which istransmitted at a full rate; f) Search for identification patterns in ahalf rate signaling block (207) which is transmitted at a half rate; g)Provision of a predetermined reference pattern for correlation; h)Subdivision of the correlation into subareas, which in turn arecorrelated by a predetermined reference pattern, in order to findsignaling frames in the full rate signaling blocks (206) and/or in thehalf rate signaling blocks (207); and i) Outputting of correlationvalues (307) in order to indicate signaling frames which have beenfound.
 2. Method according to claim 1, characterized in that mutuallyinverted identification patterns are evaluated only once, in order tosave computation time.
 3. Method according to one or both of claims 1and 2, characterized in that a sequence controller (306) makes adecision on which correlation value is used.
 4. Method according to oneor more of claims 1 to 3, characterized in that one or more of the datablocks (201 a-201 n) is a speech block or are speech blocks whichcontains or contain a speech frame or speech frames.
 5. Method accordingto one or more of claims 1 to 3, characterized in that one or more ofthe data blocks (201 a-201 n) is a signaling block or are signalingblocks which contains or contain a signaling frame or signaling frames.6. Method according to one or more of claims 1 to 3, characterized inthat deinterleaving is carried out only once.
 7. Method according to oneor more of claims 1 to 3, characterized in that the full rate signalingblock (206) contains one or more types of full rate signaling frames(208 a-208 n).
 8. Method according to one or more of claims 1 to 3,characterized in that the half rate signaling block (206) contains oneor more types of half rate signaling frames (209 a-209 n).
 9. Methodaccording to one or more of claims 1 to 3, characterized in that asequence controller decides whether to use a calculated correlationvalue.
 10. Method according to one or more of claims 1 to 3,characterized in that a speech block (204) is transmitted by means of afull rate speech block (210).
 11. Method according to one or more ofclaims 1 to 3, characterized in that a speech frame (204) is transmittedby means of a half rate speech block (211).
 12. Apparatus forrecognition of identification patterns in data blocks in order todetermine signaling frames, having: a) a receiver (202) for receiving aseries of data blocks (201 a-201 n); b) an analysis device (301) foranalysis of a specific data block from the series of data blocks (201a-201 n) in order to determine whether the specific data block containsan identification pattern (203); c) an identification device (302) foridentification of a data block which does not contain an identificationpattern (203) as a speech block (204), and for identification of a datablock which does contain an identification pattern (203) as a signalingblock (205); d) a correlation device (303) for searching foridentification patterns (203) in a full rate signaling block (206) whichis transmitted at a full rate, and for searching for identificationpatterns (203) which are contained in a half rate signaling block (207)which is transmitted at a half rate, by means of correlation with areference pattern (104); e) a correlation subdivision device (304) forsubdividing the correlation into subareas, which in turn are correlatedwith a predetermined reference pattern, in order to find signalingframes in the full rate signaling blocks (206) and/or in the half ratesignaling blocks (207); f) an output device (305) for outputtingcorrelation values (307) in order to indicate signaling frames whichhave been found; and g) a sequence controller (306) for controlling anoperating sequence and for deciding which correlation values (307) areoutput in a current state.